this repo has no description
Skip render output when nothing changes
authored by
john xu
and committed by
Tim Culverhouse
dda10d2e
11f53c70
+68
-25
+68
-25
src/Vaxis.zig
+68
-25
src/Vaxis.zig
···
360
360
assert(self.screen.buf.len == @as(usize, @intCast(self.screen.width)) * self.screen.height); // correct size
361
361
assert(self.screen.buf.len == self.screen_last.buf.len); // same size
362
362
363
-
// Set up sync before we write anything
364
-
// TODO: optimize sync so we only sync _when we have changes_. This
365
-
// requires a smarter buffered writer, we'll probably have to write
366
-
// our own
367
-
try tty.writeAll(ctlseqs.sync_set);
368
-
errdefer tty.writeAll(ctlseqs.sync_reset) catch {};
363
+
var started: bool = false;
364
+
var sync_active: bool = false;
365
+
errdefer if (sync_active) tty.writeAll(ctlseqs.sync_reset) catch {};
369
366
370
-
// Send the cursor to 0,0
371
-
// TODO: this needs to move after we optimize writes. We only do
372
-
// this if we have an update to make. We also need to hide cursor
373
-
// and then reshow it if needed
374
-
try tty.writeAll(ctlseqs.hide_cursor);
375
-
if (self.state.alt_screen)
376
-
try tty.writeAll(ctlseqs.home)
377
-
else {
378
-
try tty.writeByte('\r');
379
-
for (0..self.state.cursor.row) |_| {
380
-
try tty.writeAll(ctlseqs.ri);
381
-
}
382
-
}
383
-
try tty.writeAll(ctlseqs.sgr_reset);
367
+
const cursor_vis_changed = self.screen.cursor_vis != self.screen_last.cursor_vis;
368
+
const cursor_shape_changed = self.screen.cursor_shape != self.screen_last.cursor_shape;
369
+
const mouse_shape_changed = self.screen.mouse_shape != self.screen_last.mouse_shape;
370
+
const cursor_pos_changed = self.screen.cursor_vis and
371
+
(self.screen.cursor_row != self.state.cursor.row or
372
+
self.screen.cursor_col != self.state.cursor.col);
373
+
const needs_render = self.refresh or cursor_vis_changed or cursor_shape_changed or mouse_shape_changed or cursor_pos_changed;
384
374
385
375
// initialize some variables
386
376
var reposition: bool = false;
···
388
378
var col: u16 = 0;
389
379
var cursor: Style = .{};
390
380
var link: Hyperlink = .{};
391
-
var cursor_pos: struct {
381
+
const CursorPos = struct {
392
382
row: u16 = 0,
393
383
col: u16 = 0,
394
-
} = .{};
384
+
};
385
+
var cursor_pos: CursorPos = .{};
395
386
396
-
// Clear all images
397
-
if (self.caps.kitty_graphics)
398
-
try tty.writeAll(ctlseqs.kitty_graphics_clear);
387
+
const startRender = struct {
388
+
fn run(
389
+
vx: *Vaxis,
390
+
io: *IoWriter,
391
+
cursor_pos_ptr: *CursorPos,
392
+
reposition_ptr: *bool,
393
+
started_ptr: *bool,
394
+
sync_active_ptr: *bool,
395
+
) !void {
396
+
if (started_ptr.*) return;
397
+
started_ptr.* = true;
398
+
sync_active_ptr.* = true;
399
+
// Set up sync before we write anything
400
+
try io.writeAll(ctlseqs.sync_set);
401
+
// Send the cursor to 0,0
402
+
try io.writeAll(ctlseqs.hide_cursor);
403
+
if (vx.state.alt_screen)
404
+
try io.writeAll(ctlseqs.home)
405
+
else {
406
+
try io.writeByte('\r');
407
+
for (0..vx.state.cursor.row) |_| {
408
+
try io.writeAll(ctlseqs.ri);
409
+
}
410
+
}
411
+
try io.writeAll(ctlseqs.sgr_reset);
412
+
cursor_pos_ptr.* = .{};
413
+
reposition_ptr.* = true;
414
+
// Clear all images
415
+
if (vx.caps.kitty_graphics)
416
+
try io.writeAll(ctlseqs.kitty_graphics_clear);
417
+
}
418
+
};
399
419
400
420
// Reset skip flag on all last_screen cells
401
421
for (self.screen_last.buf) |*last_cell| {
402
422
last_cell.skip = false;
423
+
}
424
+
425
+
if (needs_render) {
426
+
try startRender.run(self, tty, &cursor_pos, &reposition, &started, &sync_active);
403
427
}
404
428
405
429
var i: usize = 0;
···
446
470
try tty.writeAll(ctlseqs.osc8_clear);
447
471
}
448
472
continue;
473
+
}
474
+
if (!started) {
475
+
try startRender.run(self, tty, &cursor_pos, &reposition, &started, &sync_active);
449
476
}
450
477
self.screen_last.buf[i].skipped = false;
451
478
defer {
···
730
757
cursor_pos.col = col + w;
731
758
cursor_pos.row = row;
732
759
}
760
+
if (!started) return;
733
761
if (self.screen.cursor_vis) {
734
762
if (self.state.alt_screen) {
735
763
try tty.print(
···
761
789
self.state.cursor.row = cursor_pos.row;
762
790
self.state.cursor.col = cursor_pos.col;
763
791
}
792
+
self.screen_last.cursor_vis = self.screen.cursor_vis;
764
793
if (self.screen.mouse_shape != self.screen_last.mouse_shape) {
765
794
try tty.print(
766
795
ctlseqs.osc22_mouse_shape,
···
1409
1438
try tty.print(ctlseqs.osc7, .{uri.fmt(.{ .scheme = true, .authority = true, .path = true })});
1410
1439
try tty.flush();
1411
1440
}
1441
+
1442
+
test "render: no output when no changes" {
1443
+
var vx = try Vaxis.init(std.testing.allocator, .{});
1444
+
var deinit_writer = std.io.Writer.Allocating.init(std.testing.allocator);
1445
+
defer deinit_writer.deinit();
1446
+
defer vx.deinit(std.testing.allocator, &deinit_writer.writer);
1447
+
1448
+
var render_writer = std.io.Writer.Allocating.init(std.testing.allocator);
1449
+
defer render_writer.deinit();
1450
+
try vx.render(&render_writer.writer);
1451
+
const output = try render_writer.toOwnedSlice();
1452
+
defer std.testing.allocator.free(output);
1453
+
try std.testing.expectEqual(@as(usize, 0), output.len);
1454
+
}